The present invention generally relates to a method and structure of semiconductor die removal and rework, specifically for dies having thicknesses of 150 micrometer and below, and to minimize the degradation of the thermal performance of a chip assembly undergoing the rework.
Previous semiconductor manufacturing processes of a wafer with multiple functional dies employ controlled chip collapse connection “C4” or “flip chip” technology to connect the semiconductor dies onto the substrate module. During rework, the semiconductors dies having 700-800 micrometer thicknesses can be removed by a mechanical rework process. This process involves placing the substrate in an upside down orientation, mechanically attaching a weighted device to the edge of the die to be removed, heating the solder joint to liquidus, and allowing the force of gravity to remove the die. Since the solder joint is liquid, there is a high surface tension between substrate and die that needs to be overcome to remove the die.